An emulsion-congealing technique is used to prepare solid lipid microparticles （SLM） containing ibuprofen with glyceryl behenate, tripalmitin and beewax as excipients. The difference of the solubility parameters bet...An emulsion-congealing technique is used to prepare solid lipid microparticles （SLM） containing ibuprofen with glyceryl behenate, tripalmitin and beewax as excipients. The difference of the solubility parameters between the excipients and ibuprofen are used to analyze their compatibility. Both the solubility parameter analysis and the experimental results show that glyceryl behenate is the best among the three excipients. The solid particles disperse well in aqueous phase when the drug loading reaches 10% （relative to lipid only）. Glycerides exhibit marked polymorphism and their rapid rates of crystallization accelerate the formation of metastable crystal modification. The metastable crystal modification characterizes high drug loading capacity but less stability. Increasing the content of lipophilic drug in a lipid matrix facilitates the transformation of excipients to more stable polymorphic forms.展开更多
The lack of an effective medical treatment for gastroparesis has pushed the research of new techniques of gastric electrical stimulation (GES) for nearly half a century of experimentation with a large variety of elect...The lack of an effective medical treatment for gastroparesis has pushed the research of new techniques of gastric electrical stimulation (GES) for nearly half a century of experimentation with a large variety of electrical stimuli delivered to the gastric wall of animals and patients with gastroparesis. Three principal methods are currently available: gastric low-frequency/high-energy GES with long pulse stimulation, high-frequency/low-energy GES with short pulse stimulation and neural sequential GES. The first method aims to reset a regular slow wave rhythm, but has variable effects on contractions and requires devices with large and heavy batteries unsuitable for implantation. High-frequency/low-energy GES, although inadequate to restore a normal gastric electro-mechanical activity, improves dyspeptic symptoms, such as nausea and vomiting, giving patients a better quality of life together with a more satisfactory nutritional status and is suitable for implantation. Unfortunately, the numerous clinical studies using this type of GES, with the exception of two, were not controlled and there is a need for definitive verification of the effectiveness of this technique to justify the cost and the risks of this procedure. The last method, which is neural sequential GES, consists of a microprocessor-controlled sequential activation of a series of annular electrodes along the distal two thirds of the stomach and is able to induce propagated contractions causing forceful emptying of the gastric content. The latter method is the most promising, but has been used only in animals and needs to be tested in patients with gastroparesis before it is regarded as a solution for this disease.展开更多
The magnetic gelatin-starch microspheres were prepared by modified emulsion cross-linking method with glutaraldehyde as the cross-linking agent. The structure, size distribution as well as morphology of magnetic micro...The magnetic gelatin-starch microspheres were prepared by modified emulsion cross-linking method with glutaraldehyde as the cross-linking agent. The structure, size distribution as well as morphology of magnetic microspheres were investigated by FT-IR spectrometer, dynamic laser scattering analyzer and scanning electron microscope, respectively. Bovine serum album(BSA)was chosen as model protein, and the adsorption processes were carried out under diversified conditions including BSA initial concentration, p H value, adsorption time and temperature to evaluate the performance of the magnetic microspheres. The average diameter of optimized spherical magnetic microspheres is 1.6 μm with excellent dispersivity, and the saturation magnetization is found to be equal to 1.056×10-2 A·m2. The adsorption isotherm of the BSA on the magnetic microspheres basically obeys the Langmuir model, with a maximum adsorption capacity of 120 mg/g and an adsorption equilibrium constant of 1.60 mL/mg.展开更多
In order to increase the electrode surface area and enhance the charge storage capacity, we study the micro electro mechanical system technology to fabricate three-dimensional high aspect ratio micro-electrode structu...In order to increase the electrode surface area and enhance the charge storage capacity, we study the micro electro mechanical system technology to fabricate three-dimensional high aspect ratio micro-electrode structure based on glass. The anodic constant potential method is employed to deposit manganese oxide as electroactive substances on the micro-electrode surface. Cyclic voltammetry and constant current charge-discharge method are both used to prepare electrode electrochemical performance testing, with a two-dimensional electrode without structure for comparison. Experimental results show that three-dimensional elec- trode structure can effectively enhance the charge storage capacity. At 1.0 mA/cm2 charge- discharge density, the three-dimensional electrode shows a capacitance of 17.88 mF/cm2, seven times higher than the two-dimensional electrode.展开更多
In the established apparatus, the conversion ratios of cellulose sulfation (X) under different sulfation conditions were measured. The range of temperature was from -5℃ to +5℃, and the H2SO4 concentration was from 3...In the established apparatus, the conversion ratios of cellulose sulfation (X) under different sulfation conditions were measured. The range of temperature was from -5℃ to +5℃, and the H2SO4 concentration was from 3.1 mol·L-1 to 4.5mol·L-1. The experimental results were used for the establishment of the kinetic model for cellulose sulfation. With the model, X values and the yield of NaCS (Y) can be calculated, thus the reaction with respect to H2SO4 concentration is determined to be third order.展开更多
Mini centrifugal pumps having a diameter smaller than lOOmm are employed in many fields. But the design method for the mini centrifugal pump is not established because the internal flow condition for these small-sized...Mini centrifugal pumps having a diameter smaller than lOOmm are employed in many fields. But the design method for the mini centrifugal pump is not established because the internal flow condition for these small-sized fluid machines is not clarified and conventional theory is not suitable for small-sized pumps. Therefore, mini cen- trifugal pumps with simple structure were investigated by this research. Splitter blades were adopted in this re- search to improve the performance and the internal flow condition of mini centrifugal pump which had large blade outlet angle. The original impeller without the splitter blades and the impeller with the splitter blades were prepared for experiment. The performance tests are conducted with these rotors in order to investigate the effect of the splitter blades on performance and internal flow condition of mini centrifugal pump. On the other hand, a three dimensional unsteady numerical flow analysis was conducted to investigate the change of the internal flow according to the rotor rotation. It is clarified from the experimental results that the performance of the mini cen- trifugal pump is improved by the splitter blades. The blade-to-blade low velocity region was suppressed in the case with the splitter blades. In addition to that, the unsteady flows near the volute casing tongue were suppressed due to the splitter blades. In the present paper, the performance of the mini centrifugal pump is shown and the un- steady flow condition is clarified with the results of the numerical flow analysis. Furthermore, the effects of the splitter blades on the performance and the unsteady internal flow condition are investigated.展开更多
The capacity of supercapacitor charge storage depends on the size of the electrode surface area and the active material on the electrodes.To enhance the charge storage capacity with a reduced volume,silicon is used as...The capacity of supercapacitor charge storage depends on the size of the electrode surface area and the active material on the electrodes.To enhance the charge storage capacity with a reduced volume,silicon is used as the electrode material,and three-dimensional electrode structure is prepared to increase the electrode surface area on the footprint area by inductively coupled plasma reactive etching(ICP) techniques.The anodic constant current deposition method is employed to deposit manganese oxide on the electrode surface as the electroactive material.For comparison,samples without slot are prepared with a two-dimensional electrode.Scanning Electron Microscopy(SEM) and Energy Dispersive Spectroscopy(EDS) are used to characterize the surface morphology of the electrode structure and the deposited electroactive material.Electrochemical properties of the electrode are characterized by the cyclic voltammetry(CV) and the constant current charge-discharge method.Experimental results show that our approach can effectively increase the electrode surface area with more electroactive substances,and hence can increase storage capacity of the micro-supercapacitor.展开更多
By citrate sol-gel auto-combustion method,the nanophase M-type planar hexagonal ferrite is prepared.The transmission electron microscopy(TEM),X-ray diffraction(XRD) and thermal analysis are used to study the grain siz...By citrate sol-gel auto-combustion method,the nanophase M-type planar hexagonal ferrite is prepared.The transmission electron microscopy(TEM),X-ray diffraction(XRD) and thermal analysis are used to study the grain size,phase composition,microstructure and crystallization process.The results show that the nanophase M-type Sr-ferrite prepared by this method is single,and its grain size is smaller than 100 nm.Moreover,most of the grains present hexagonal sheet shape.Tests are carried out for its attenuation to 1.06 mm laser.It is found that the extinction capability of the nanophase M-type Sr-ferrite smoke is good,and its mass extinction coefficient is 1.628 m2/g.展开更多
基金Supported by the National Natural Science Foundation of China （No.20536020, No.20476033）, the China Distinguished Young Scientist Fund （No.20225620） and Guangdong Province Science Fund （No.04020121）.
文摘An emulsion-congealing technique is used to prepare solid lipid microparticles （SLM） containing ibuprofen with glyceryl behenate, tripalmitin and beewax as excipients. The difference of the solubility parameters between the excipients and ibuprofen are used to analyze their compatibility. Both the solubility parameter analysis and the experimental results show that glyceryl behenate is the best among the three excipients. The solid particles disperse well in aqueous phase when the drug loading reaches 10% （relative to lipid only）. Glycerides exhibit marked polymorphism and their rapid rates of crystallization accelerate the formation of metastable crystal modification. The metastable crystal modification characterizes high drug loading capacity but less stability. Increasing the content of lipophilic drug in a lipid matrix facilitates the transformation of excipients to more stable polymorphic forms.
文摘The lack of an effective medical treatment for gastroparesis has pushed the research of new techniques of gastric electrical stimulation (GES) for nearly half a century of experimentation with a large variety of electrical stimuli delivered to the gastric wall of animals and patients with gastroparesis. Three principal methods are currently available: gastric low-frequency/high-energy GES with long pulse stimulation, high-frequency/low-energy GES with short pulse stimulation and neural sequential GES. The first method aims to reset a regular slow wave rhythm, but has variable effects on contractions and requires devices with large and heavy batteries unsuitable for implantation. High-frequency/low-energy GES, although inadequate to restore a normal gastric electro-mechanical activity, improves dyspeptic symptoms, such as nausea and vomiting, giving patients a better quality of life together with a more satisfactory nutritional status and is suitable for implantation. Unfortunately, the numerous clinical studies using this type of GES, with the exception of two, were not controlled and there is a need for definitive verification of the effectiveness of this technique to justify the cost and the risks of this procedure. The last method, which is neural sequential GES, consists of a microprocessor-controlled sequential activation of a series of annular electrodes along the distal two thirds of the stomach and is able to induce propagated contractions causing forceful emptying of the gastric content. The latter method is the most promising, but has been used only in animals and needs to be tested in patients with gastroparesis before it is regarded as a solution for this disease.
基金Project(GC201204)supported by the Open Fund of Guangdong Provincial Key Laboratory for the Green Chemicals,China
文摘The magnetic gelatin-starch microspheres were prepared by modified emulsion cross-linking method with glutaraldehyde as the cross-linking agent. The structure, size distribution as well as morphology of magnetic microspheres were investigated by FT-IR spectrometer, dynamic laser scattering analyzer and scanning electron microscope, respectively. Bovine serum album(BSA)was chosen as model protein, and the adsorption processes were carried out under diversified conditions including BSA initial concentration, p H value, adsorption time and temperature to evaluate the performance of the magnetic microspheres. The average diameter of optimized spherical magnetic microspheres is 1.6 μm with excellent dispersivity, and the saturation magnetization is found to be equal to 1.056×10-2 A·m2. The adsorption isotherm of the BSA on the magnetic microspheres basically obeys the Langmuir model, with a maximum adsorption capacity of 120 mg/g and an adsorption equilibrium constant of 1.60 mL/mg.
文摘In order to increase the electrode surface area and enhance the charge storage capacity, we study the micro electro mechanical system technology to fabricate three-dimensional high aspect ratio micro-electrode structure based on glass. The anodic constant potential method is employed to deposit manganese oxide as electroactive substances on the micro-electrode surface. Cyclic voltammetry and constant current charge-discharge method are both used to prepare electrode electrochemical performance testing, with a two-dimensional electrode without structure for comparison. Experimental results show that three-dimensional elec- trode structure can effectively enhance the charge storage capacity. At 1.0 mA/cm2 charge- discharge density, the three-dimensional electrode shows a capacitance of 17.88 mF/cm2, seven times higher than the two-dimensional electrode.
基金Supported by the National Natural Science Foundation of China(No.29676069).
文摘In the established apparatus, the conversion ratios of cellulose sulfation (X) under different sulfation conditions were measured. The range of temperature was from -5℃ to +5℃, and the H2SO4 concentration was from 3.1 mol·L-1 to 4.5mol·L-1. The experimental results were used for the establishment of the kinetic model for cellulose sulfation. With the model, X values and the yield of NaCS (Y) can be calculated, thus the reaction with respect to H2SO4 concentration is determined to be third order.
文摘Mini centrifugal pumps having a diameter smaller than lOOmm are employed in many fields. But the design method for the mini centrifugal pump is not established because the internal flow condition for these small-sized fluid machines is not clarified and conventional theory is not suitable for small-sized pumps. Therefore, mini cen- trifugal pumps with simple structure were investigated by this research. Splitter blades were adopted in this re- search to improve the performance and the internal flow condition of mini centrifugal pump which had large blade outlet angle. The original impeller without the splitter blades and the impeller with the splitter blades were prepared for experiment. The performance tests are conducted with these rotors in order to investigate the effect of the splitter blades on performance and internal flow condition of mini centrifugal pump. On the other hand, a three dimensional unsteady numerical flow analysis was conducted to investigate the change of the internal flow according to the rotor rotation. It is clarified from the experimental results that the performance of the mini cen- trifugal pump is improved by the splitter blades. The blade-to-blade low velocity region was suppressed in the case with the splitter blades. In addition to that, the unsteady flows near the volute casing tongue were suppressed due to the splitter blades. In the present paper, the performance of the mini centrifugal pump is shown and the un- steady flow condition is clarified with the results of the numerical flow analysis. Furthermore, the effects of the splitter blades on the performance and the unsteady internal flow condition are investigated.
文摘The capacity of supercapacitor charge storage depends on the size of the electrode surface area and the active material on the electrodes.To enhance the charge storage capacity with a reduced volume,silicon is used as the electrode material,and three-dimensional electrode structure is prepared to increase the electrode surface area on the footprint area by inductively coupled plasma reactive etching(ICP) techniques.The anodic constant current deposition method is employed to deposit manganese oxide on the electrode surface as the electroactive material.For comparison,samples without slot are prepared with a two-dimensional electrode.Scanning Electron Microscopy(SEM) and Energy Dispersive Spectroscopy(EDS) are used to characterize the surface morphology of the electrode structure and the deposited electroactive material.Electrochemical properties of the electrode are characterized by the cyclic voltammetry(CV) and the constant current charge-discharge method.Experimental results show that our approach can effectively increase the electrode surface area with more electroactive substances,and hence can increase storage capacity of the micro-supercapacitor.
文摘By citrate sol-gel auto-combustion method,the nanophase M-type planar hexagonal ferrite is prepared.The transmission electron microscopy(TEM),X-ray diffraction(XRD) and thermal analysis are used to study the grain size,phase composition,microstructure and crystallization process.The results show that the nanophase M-type Sr-ferrite prepared by this method is single,and its grain size is smaller than 100 nm.Moreover,most of the grains present hexagonal sheet shape.Tests are carried out for its attenuation to 1.06 mm laser.It is found that the extinction capability of the nanophase M-type Sr-ferrite smoke is good,and its mass extinction coefficient is 1.628 m2/g.
